Parity-Induced Exceptional Points with Localized Loss

Abstract:We explore the existence and stability of exceptional points (EPs) in finite waveguide arrays subject to single-site dissipation using an exact Laplace-transform framework. We show that the EP landscape is governed by a parameter-free Wronskian condition and a geometry-dependent parity effect, yielding strictly distinct spectral behaviors for even versus odd numbers of waveguides. Specifically, odd chains with edge loss suppress coalescence via a protected central mode, whereas even chains with central loss feature a universal threshold that gives rise to imaginary zero modes. These findings clarify the fundamental rules of non-Hermitian symmetry breaking in finite systems, offering a deterministic framework to predict, engineer, or avoid spectral singularities in integrated photonic lattices.

Optics (physics.optics); Quantum Physics (quant-ph)

arXiv:2601.09628 [physics.optics]

(or arXiv:2601.09628v2 [physics.optics] for this version)

https://doi.org/10.48550/arXiv.2601.09628 Focus to learn more arXiv-issued DOI via DataCite

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